Method and apparatus for producing x-ray photographs



G. V. BUTLER April 1, 1958 METHOD AND APPARATUSVFOR PRODUCING X-RAY PHOTOGRAPHS Filed Oct. 12, 1954 2 Sheets-Sheet 1 INVENTOR. GEORGE W BUTLER ATTORII'Y April 1, 1958 e. v. BUTLER METHOD AND APPARATUS FOR PRODUCING X-RAY PHOTOGRAPHS l iled Oct. 12, 1954 2 Sheets-Sheet 2 mnmmum .ll lllllt:

INVENTOR. GEORGE V. BUTLER ATTORNEY Fla] United States Patent METHOD AND APPARATUS FOR PRODUCING X-RAY PHOTOGRAPHS George V. Butler, Rochester, N. Y. Application October 12, 1954, Serial No. 461,770

Claims. (Cl. 25065) My invention relates to a method of and apparatus for making X-ray photographs, particularly X-ray photographs of the dental arches.

While the principles of my invention may have appli cation to X-rays of other portions of the body and may have application in making industrial X-rays for certain purposes, it has primarily been developed for the purpose of making X-ray photographs of the dental arches.

The modern dentist has become more and more dependent upon employing X-rays to enable him to make a diagnosis of the exact condition of the teeth and associated structures of the upper and lower jaws. Tooth decay and abscessed teeth are not always superficially evident and many dentists now insist upon making X-rays prior to doing any work on the teeth of patients.

Because of the' curvature of the dental arches and the limitation of the angle which an X-ray photograph may encompass, invariably the dentist must make a number of X-ray photographs in order to make a complete diagnosis.- Some dentists insist upon making as many as fourteen separate photographs to encompass both upper and lower dental arches. This is done primarily so that the teeth will appear approximately in their proper relationship on the photographs and portions of the teeth will not be hidden by adjacent teeth due to the curvature of the dental arches. In some cases where exact locations of parts of the teeth must be determined by measurements on the film, distortion due to the curvature of the dental arches must be further reduced by taking as many as eighteen separate X-rays.

Not only is the process which is presently employed time-consuming because of the requirement for so many X-rays but also there are technical difficulties because the film packs must be within the mouth of the patient and must be held in position by the patient gripping with his teeth the tab or bite with which each film pack is provided. Not only must the dentist locate the film pack reasonably accurately in the mouth of the patient but also the patient must cooperate and hold the pack in the required position. Quite frequently the film pack is not located and held accurately and defective photographs result. Moreover, errors by the dentist occasionally occur due to the fact that the dentist has a largenumber of X-ray photographs to handle and must assemble them in the proper relationship so that the teeth appear in the photographs in the same order in which they exist in the mouth of the patient. While the film pack manufacturer does provide reference indicia in order that films may be arranged in the proper order, errors do occur. It is constantly necessary for the dentist to keep in mind the relationship of the teeth on the numerous X-rays because all of the teeth appear on each of at least two films.

In recent years mechanism hasbeen developed for taking-so-called panoramic photographs of the dental arches. These mechanisms are complicated and expensive since they involve means for rotating the X-ray cone and tube'in an annular path conforming to the curvature of the dental arches. Because of the expense and complication of such panoramic X-ray units, their use by the average dentist is not justified. Such units can be employed profitably only where the teeth of a large number of patients are to be X-rayed in succession, as for example, in schools and military establishments.

An object of my invention is to provide a method and apparatus for making X-ray photographs of parts of the body, particularly the dental arches or other objects to be X-rayed which lie in different planes, in a single exposure.

Another object of my invention contemplates the pro A vision of simple and inexpensive apparatus which may be employed with the method of my invention to enable a dentist, in one exposure to make an X-ray photograph of both the upper and lower dental arches simultaneously to the end that the time of the dentist in making X-ray photographs is conserved, the patient is saved the annoyance of the dentist making a number of successive exposures, the possibility of mistakes by the dentist due to the necessity of assembling a large number of X-rays in proper sequence is avoided, a saving in film is effected and the exposure time is reduced.

More specifically my invention contemplates the employment of means located internally of the confines of the dental arches for receiving X-rays from the tube of an X-ray unit and redirecting them in an are or arcs encompassing both the upper and lower dental arches with the film positioned externally of the dental arches whereby one X-ray image of both dental arches may be obtained in a single exposure.

Other objects and advantages of my invention will be particularly set forth in the claims and will be apparent from the following description, when taken in connection with the accompanying drawings, in which:

Fig. l is a perspective view of one form of apparatus which may be used to carry out the method of my invention in connection with the making of X-ray photographs of the dental arches;

Fig. 2 is a sectional view taken substantially onthe line 22'of Fig. 1 and indicating how the apparatus of my invention may be applied to a patient and showing the position of the X-ray cone;

Fig. 3 is a sectional view of the means for receiving X-rays and redirecting them from a position internally of the dental arches in an arc encompassing both dental arches;

Fig. 4 is a sectional view taken substantially on the line 4-4 of Fig. 3 and showing in dotted lines the lower dental arch;

Fig. 5 is a sectional view showing a suitable film pack or cassette for use in carrying out the method of my invention;

Fig. 6 is an elevational view of Fig. 5; and

Fig. 7 is a diagrammatic illustration of an X ray photograph produced by the method of my invention.

While the principles of my. invention may be employed in making X-rays of other portions of the body and other objects, as previously mentioned, it has been developed primarily for making X-rays of the dental arches. The apparatus for carrying out the method of my invention has been illustrated somewhat diagrammatically and comprises an X-ray unit which has not been shown except for the cone 11 thereof, means generally indicated by the numeral 13 for receiving and redirecting the X-rays emanating from the cone, a mounting generally indicated by the numeral 14- for supporting the ray-receiving and redirecting means 13, and a film pack or cassette generally indicated by the numeral 16.

The X-rayapparatusadapted to carry out my invention (not shown except for the cone .11 thereof) may be of conventional design and need not be described, since apparatus suitable for my purpose is well known and is manufacturedby a number of different companies.

As shown in Fig. l the cone: of the X-ray is directed upwardly from beneath the chin as this is the minimum distance path to the plane of the dental arches and bone 1 interference is avoided when the primary rays are thus directed. While the primary rays, .as indicated by the numeral 17,,are directed substantially normal to the plane of .the dental arches, it would be possible to direct the primary beam at another angle and reorient the X-ray receiving and redirecting means which will be presently described. Throughout the specification and claims the plane of the dental arches will be considered the approximate plane defined by theJmeeting edges of the upper and lower sets of teeth or the bite plane.

As is well known in the art to which this invention applies, when the rays emanating from the cone of the X-ray unit enter the flesh they are scattered in accordance with well known principles. However, for the purposes of .my invention, this initial scattering effect can be ignored. The primary beam 17 is directed toward a target, generally indicated by the numeral 18, constituting part of the ray-receiving and redirecting means generally indicated by the numeral13.

The target member 18 or ray-receiving and redirecting means (Figs. 3, 4) comprises a lead core 19 and upper and lower lead shields .20 and 21 and a segment 22. The core 19 is surrounded with an annular ring 23 of scattering material. Scattering agents or materials are well known in the art. All materials exert a scattering efiect on X-rays but the materials suitable for my purposes arc those in general which produce a maximum of scattering. I have experimented with colloidal gold, magnesium, carbon and lithiumsalts and found all of them to be useful for my purposes, although many other materials :may be used. Ideally the scattering material should consist of substances which produce the same or a similar scattering effect to that produced by the tooth and bone structure to be penetrated. I thus contemplate employing materials of approximately the same density as the teeth and bone structure being X-rayed, such as calcium phosphate or perhaps .tooth or bone material itself.

Extending in surrounding relation to the annular ring 23 of scattering material are upper and lower segments 24. of radiolucent material. Plastics have been found suitable for this purpose and in fact the segments may be filled with any radiolucent material, air being a suitable medium to transmit theX-rays scattered by the annular ring 210i scattering material. Between each adjacent segment 24 a lead partition 25 is provided which confines thescattered rays directed through the radiolucent material 24. k The purpose of the lead separators 25 and the lead shields 21 and 22 is to permit the emission of only usefully directed rays, insofar. as possible, through the shielded openings, that is, rays directed essentially at right angles to the teeth and bone. By eliminating, insofar as possible all but the usefully directed rays, definition of the images of the teeth and bone formed on the film is increased. a

The X-ray receiving and redirecting means above. described has been found tobe very satisfactory for my purposes. However, it might be possible to eliminate the core 19 and instead of employing an annular ring 23 of scattering material, employ a smalLdiameter cylinder of scattering material. centrally located in the target member. 18 Moreover, it might bepossible to substitute for the scattering agent a system of crystals so oriented as to redirect the rays in an arc encompassing the dental arches.

The ray receiving and redirecting unit or target member 18 is supported by a radiopaque plate 26 of lead or any other suitable material. The plate 26 divides the rays redirected by the annular scattering ring 23 into an upper and a lower are of rays, the upper arc encompassing the upper dental arch and the lower arc encompass ing the lower dental arch.

The plate 26 is preferably supported in the mouth of the patient. Such support for the plate 26 may comprise the mounting generally indicated by the numeral 14. The mounting may comprise a support 27 having a suitable cut-out 28 conforming to the curvature of the chin.

The mounting 14 may be carried by the X ray unit so that it may be swung into position when the cone of the X-ray unit is oriented beneath the chin of the patient. Thus the mounting 14 may .be maintained in fixed relation to the cone 11. The support or mounting carries preferably a pair of brackets 29 and 31 defining a slot 32 between them. The inner bracket 31 is radiolucent so as not to cut off the front teeth .of the lower dental arch. The inner bracket 31 is turned inward at 33 in a horizontal plane and carries the radiopaque plate 26 as shown at 34.

The film pack or cassette, generally indicated by the numeral 16, is flexible and in general rectangular as shown in Fig. 6. It may be provided at its ends with apertured tabs 36 for receiving a cord which may be tied in the back of the neck. The film pack 16 comprises a pair of light locking shields 37 of heavy black paper or flexible light-proof material. These shields are U-shaped in section and are telescoped with respect to each other in opposed relation so that light cannot gain access to the film3 3. The film is preferably enclosed between flexible intensifying screens 39. The purpose of the intensifying screens is to improve speed and reduce exposure time. Their construction and purpose is well known in the art to which this invention applies.

From the foregoing it is believed that the principles of my invention will be clear. The film produced has been shown in Fig. 7. By employing the principles of my invention both dental arches may be X-rayed in one exposure. The X-ray-receiving and redirecting unit 18 is easily located in the oral cavity and when the mounting 14 and the Xray unit are held in fixed relation the possibility of error is to a large extent eliminated.

While I have described the principles of my invention and shown one form of apparatus suitable for my purposes, it is obvious that various changes may be made, particularly in the form and relationship of the elements. For example, it might be possible to employ a film pack to be carried within the oral cavity externally of the dental arches. This and other variations will occur to those skilled in the art and are intended to be included within the scope of the appended claims.

I claim:

1. Apparatus for making X-ray photographs of the dental arches comprising, in combination, a support, means for supporting said support within the oral cavity, a scattering agent carried by said support for receiving X-rays directed at an angle to a plane parallel to the plane of the upper and lower dental arches and redirect ing them in an arc embracing said dental arches, and means for supporting film in an arc encompassing said dental arches.

2. Apparatus in accordance with claim 1 in which the scattering agent comprises a central annular ring of scattering material and segmental scattering confining members radiating from said annular ring.

3. Apparatus in accordance with claim 1 in which the film is enclosed within a light tight flexible enclosure.

4. Apparatus in accordance with claim 1 in which the film is enclosed within a light tight enclosure and an intensifying screen is on each side of the film and within the enclosure.

5. Apparatus in accordance with claim 1 in which, the scattering agent is of such character that it produces approximately the same scattering as the teeth and bone being penetrated.

6. Apparatus for making X-ray photographs of the dental arches comprising, in combination, a support, a pair of members extending upwardly from said support and defining a slot between them, a film supported in said slot and extending externally of the mouth and encompassing the dental arches, one of said members extending inwardly into the mouth and carrying a plate, and means carried by said plate for receiving X-rays emanating from a source located beneath the chin and redirecting them fanwise in an arc embracing said dental arches.

7. Apparatus in accordance with claim 6 in which the plate lies substantially in a plane substantially between the upper and lower dental arches and is radiopaque and said last mentioned means confine rays both above and below the plate.

8. Apparatus for making X-ray photographs of both dental arches in one exposure comprising, in combination, means for directing X-rays in an upward direction from beneath the chin, means within the confines of the dental arches for receiving said rays and redirecting them in an arc encompassing said dental arches and a film located in an arc externally of and encompassing said dental arches.

9. Apparatus in accordance with claim 8 in which the redirected rays are confined by essentially cone-shaped radiopaque members arranged in an are about a central axis.

10. Apparatus in accordance with claim 8 in which the ray receiving and redirecting means is a scattering agent extending essentially in an upward direction and defining a substantially cylindrical source of scattered rays and means are provided extending radially with respect to said cylindrical source of scattered redirected rays for confining them and reducing the scattering eflect on the rays directed toward the dental arches.

References Cited in the file of this patent UNITED STATES PATENTS 1,408,559 Zulauf Mar. 7, 1922 2,476,776 Smathers July 19, 1949 2,574,681 Zinn Nov. 13, 1951 2,638,554 Bartow et al. May 12, 1953 2,684,446 Paatero July 20, 1954 

